Thyroid Nodules

A thyroid nodule is a lump found in the gland. They can be malignant (cancer) or benign (not cancer). Although thyroid nodules are more common in adults than children, they are more likely (20-30%) to be malignant in children. It is important to be able to tell the difference between a discrete lump and general enlargement of the entire gland, which is seen with multiple nodules (nontoxic goiter), hyperthyroidism, or Hashimoto’s thyroiditis. Blood tests are often ordered in these children to check the hormone levels. These tests are usually normal with a thyroid nodule. Nuclear medicine studies (a type of radiology study) are often ordered to differentiate “hot” (increased activity on the study) from “cold” nodules (little or no activity on the study). A “cold” nodule can indicate certain types of disease including, papillary carcinoma, a follicular adenoma (benign) or carcinoma, or a colloid nodule (benign). Ultrasound may also be used to demonstrate cystic disease (also “cold”), although cysts are rare in children. “Hot” nodules are rare in children as well, and indicate autonomous function (function beyond the body’s normal check and balances).

Papillary carcinoma is the most common type of cancer in children. It presents with a nodule, diffuse enlargement of one lobe, or with enlargement of the gland with enlarged lymph nodes. Enlarged lymph nodes can be felt in the neck in many children with papillary carcinoma. Thyroid studies from the blood are usually normal in papillary carcinoma. Increased antibody levels (antimicrosomal) indicate Hashimoto’s disease. Papillary carcinoma is usually solid on ultrasound, but cystic disease can occur as well. Nuclear medicine studies (thyroid scans) are usually “cold” in papillary carcinoma.

Fine-needle aspiration (FNA) is a method to biopsy a nodule to make a diagnosis. A very small needle is passed into the nodule and cells from the nodule are sucked into a syringe. These cells can then be looked at under a microscope. FNA has been done more frequently in adults than children. This is a low-risk procedure done in the office with local anesthesia. If a nodule is cystic, it may completely go away after removal of the fluid with a needle. If solid, aspiration of cells with the needle may diagnose papillary or medullary carcinoma, although it may not be sufficient to differentiate benign and malignant disease (especially with follicular disease of the thyroid).

Discrete, benign thyroid nodules in adults are treated with synthroid to suppress the nodule and make it decrease in size. This is rarely indicated or effective in childhood. In the setting of enlargement of the entire gland from stimulation (by Thyroid Stimulating Hormone-TSH), thyroid suppression may be successful.